Thermal ablation system with dispensable therapeutic

ABSTRACT

A cassette for a heated fluid ablation system, comprises a fluid supply lumen receiving an ablation fluid from an external fluid source and a fluid chamber containing a therapeutic agent in combination with an impeller pumping the ablation fluid out of the cassette via to a fluid delivery lumen when the cassette is in a first configuration and pumping the therapeutic agent out of the cassette via the fluid delivery lumen when the cassette is in a second configuration.

PRIORITY CLAIM

The present application is a Continuation of U.S. patent applicationSer. No. 12/206,315 filed on Sep. 8, 2008, now U.S. Pat. No. 8,628,311;which claims the priority of U.S. Provisional Application Ser. No.60/971,372, filed Sep. 11, 2007. The entire disclosure of thesepatents/applications are expressly incorporated herein by reference.

BACKGROUND

Although hysterectomy is generally an effective treatment formenorrhagia, less invasive procedures are often preferable as theyreduce side effects, hospital stays and procedural and post-operativediscomfort.

Less invasive procedures treat affected areas of the uterus employingelectrical energy (e.g., RF energy), heat (e.g., laser) or cryogenictreatment. However, these procedures typically rely on directvisualization of the uterus by an experienced operator to ensure thatthe energy is applied to the affected areas of the uterine lining.Alternatively, the entire lining of the uterus may be treated byconduction uterine ablation, i.e., circulation of a heated fluid throughthe uterus or within a balloon inserted into the uterus.

SUMMARY OF THE INVENTION

The present invention relates to a cassette for a heated fluid ablationsystem, comprising a fluid supply lumen receiving an ablation fluid froman external fluid source and a fluid chamber containing a therapeuticagent in combination with an impeller pumping the ablation fluid out ofthe cassette via to a fluid delivery lumen when the cassette is in afirst configuration and pumping the therapeutic agent out of thecassette via the fluid delivery lumen when the cassette is in a secondconfiguration.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 shows an exemplary embodiment of a thermal ablation systemaccording to the present invention;

FIG. 2 shows a frontal view of an exemplary embodiment of a console of athermal ablation system according to the present invention;

FIG. 3 shows an exploded view of an exemplary embodiment of a console ofa thermal ablation system according to the present invention;

FIG. 4 shows an exploded view of an exemplary embodiment of a right sidecomponent of a console of a thermal ablation system according to thepresent invention;

FIG. 5 shows an exploded view of an exemplary embodiment of a valveassembly for a console of a thermal ablation system according to thepresent invention;

FIG. 6 shows an exploded view of an exemplary embodiment of a front sidecomponent of a console of a thermal ablation system according to thepresent invention;

FIG. 7 shows an exploded view of an exemplary embodiment of a chassis ofa console of a thermal ablation system according to the presentinvention;

FIG. 8 shows an outer view of an exemplary embodiment of a cassette of athermal ablation system according to the present invention;

FIG. 9 shows an inner view of an exemplary embodiment of a cassette of athermal ablation system according to the present invention;

FIG. 10 shows an exemplary embodiment of an introducer of a thermalablation system according to the present invention;

FIG. 11 shows an exemplary embodiment of an open loop fluid flow path ofa thermal ablation system according to the present invention;

FIG. 12 shows an exemplary embodiment of a closed loop fluid flow pathof a thermal ablation system according to the present invention;

FIG. 13 shows an exemplary embodiment of fluid flow through a heatingchamber in a cassette according to the present invention;

FIG. 14 shows an exemplary embodiment of an impeller of a thermalablation system according to the present invention;

FIG. 15 shows an exemplary embodiment of an impeller of a thermalablation system according to the present invention; and

FIG. 16 shows an exemplary embodiment of a cervical seal of a thermalablation system according to the present invention.

DETAILED DESCRIPTION

The present invention may be further understood with reference to thefollowing description and to the appended drawings, wherein likeelements are referred to with the same reference numerals. The presentinvention relates to systems, methods and apparatus for applying one ormore therapeutic agents to tissue, e.g., tissue lining an inner surfaceof a hollow organ which has been subjected to ablative energy. In oneexemplary embodiment, the present invention relates to devices forablating the endometrial lining using a first fluid (e.g., heatedsaline) and applying a therapeutic agent to the remaining exposedsurface uterine tissue after the ablation. While the exemplaryembodiments will be described with reference to applying the therapeuticagent after a tissue ablation procedure, those of skill in the art willunderstand that the present invention, or components thereof, may beutilized in prostate treatment (microwave or cyroablation) systems,irrigation systems or other procedures which would benefit from applyinga therapeutic agent or other fluid, gel, etc. to a tissue prior to,during and/or after a surgical procedure. Those skilled in the art willunderstand that the term “therapeutic agent” as used throughout thespecification, encompasses any nutritive, cleansing, pharmaceutic fluid,gel, etc. which provides a therapeutic effect. Thus, any of saline,water, blood products, nutritive solutions, drugs or combinations of anyof these may be employed as a therapeutic agent as that term is usedherein.

FIG. 1 shows an exemplary embodiment of a thermal ablation system 2according to the present invention. Generally, the system 2 includes aconsole 4 having a pole 6 extending from an upper portion thereof and astand 8 coupled to a lower portion thereof. The pole 6 preferablyextends to a predetermined height above the console 4 so that anintravenous (IV) bag (not shown) hung therefrom will supply fluid to theconsole 4 at a desired pressure. The IV bag contains fluid (e.g.,saline) that will be heated and circulated through the uterus to ablatethe endometrial lining. During the ablation procedure, an operator(e.g., physician, nurse, etc.) may be required to substitute the IV bagfor IV bags with other fluids depending on stage of the ablationprocedure. The IV bags for any fluids required during the procedure maybe concurrently attached to the pole 6 with the height of the pole 6determining the pressure at which these fluids will be supplied to theconsole 4.

A height of the console 4 relative to the floor is preferably variableusing a height-adjusting mechanism between the stand 8 and the console 4to control a pressure of fluid reaching the treatment site as will bedescribed below. The height-adjusting mechanism may be a pneumatic lift,a frictional lock, etc., allowing the operator to manually adjust of theheight of the console 4. In another exemplary embodiment, theheight-adjusting mechanism may comprise an automated height adjustmentmechanism controlled by user actuation or automatically by electroniccircuitry (e.g., in the console 4) based on sensor data, etc.

In the exemplary embodiment, the stand 8 is provided with a mobile base10 (e.g., locking wheels) so that the system 2 is easily moveable andsteerable. However, those of skill in the art will understand that thebase 10 may be static or that electronic control and movement of thesystem 2 may also be implemented.

As shown in FIG. 2, the console 4 according to the present inventioncomprises a housing 10 encasing electronic circuitry and providing auser interface 12 for displaying content (e.g., instructions, proceduraldata, warnings, etc.) and receiving user input. The user interface 12may comprise a display screen 14 (e.g., LCD) and a keypad 16 forsubmitting input to the console 4. Those of skill in the art willunderstand that the keypad 16 may be replaced or augmented by dials,switches, a touch screen (or the screen 14 may be made responsive totactile input) or any other controls operable by the operator of thesystem 2. In one exemplary embodiment, a disposable overlay (not shown)may be applied over the user interface 12. For example, if the displayscreen 14 is a touch screen and the operator intermittently providesinput to the user interface 12 by touching the display screen 14, anoverlay may be used to prevent the display screen 14 from becomingdamaged or obscured by fluid.

The housing 10 may further include a handle 18 for steering the system 5and a slot 26 receiving a cassette 28, which is described below. In theexemplary embodiment, the handle 18 includes an alignment beam activator20 which, when pressed, causes a light beam (e.g., laser light) to beemitted from a beam exit port 24 on the console 4. As would beunderstood by those skilled in the art, the light beam may preferably beoriented horizontally so that, as the height of the console 4 isadjusted using the height adjusting mechanism on the stand 8 until thebeam is positioned on a desired portion of the patient's anatomy, theoperator will know that the console 4 is in a desired position relativeto the uterus (e.g., level with the uterus). Making the console 4 adesired height off the floor relative to the uterus (e.g., the sameheight) ensures that a pressure at which the fluid is circulated in theuterus does not exceed a predetermined value. Those of skill in the artwill understand that the activator 20 may be disposed adjacent to theuser interface 12 and/or the keypad 16 or may be positioned on thehandle 18. The housing 10 preferably also includes a hook 22 for hanginga drainage bag (not shown) from the console 4. After ablating theendometrial lining, the fluid is discharged into the drainage bag.

FIG. 3 shows internal components of an exemplary console 4 according tothe present invention. The housing 10 of the console 4 includes a frontside 30, a rear side 32, a left side 34 and a right side 36. Those ofskill in the art will understand that the housing 10 may be comprised ofany number of components in any number of geometrical relationships toone another and that the terms front, rear, left and right arerelational terms used only to describe the exemplary embodiment of theconsole 4. A chassis 38 inside the housing 10 acts as an attachmentpoint for the sides 30, 32, 34, 36 and supports various electricalcomponents of the console 4. In this embodiment, the front side 30includes circuitry powering the user interface 12 and the beam activator20, while the rear side 32 provides an input for a power source (e.g.,line voltage). However, in other exemplary embodiments, the system 2 maybe powered by an on-board battery. The left side 34 generally comprisesa vented wall which allows air heated during operation of the electriccomponents of the console 4 to be expelled therefrom, while the rightside 36 includes components that interface with the cassette 28.

FIG. 4 shows an exemplary embodiment of the right side 36 of the console4 which includes components for interfacing with the cassette 28. Thecassette interface generally includes a valve arrangement 40 and a motorarrangement 42. The valve arrangement 40 includes one or more valves 46(e.g., pinch valves) which engage outer surfaces of flexible tubeswithin the cassette 28 via openings in a rigid housing thereof toselectively open and close the tubes without contacting fluids flowingtherethrough. As shown in FIG. 5, an exemplary valve assembly 50 is apinch valve. However, those of skill in the art will understand that thefunctions of the valves 46 may be performed by any device(s) configuredto selectively open and close the tubes in the cassette 28 withoutcontacting fluids within the tubes.

As shown in FIG. 5, the valve assembly 50 includes a motor 52 whichdrives rotation of a pinion 54 that mates with a rack 56. Rotation ofthe pinion 54 is translated into axial movement of the rack 56 in distal(lumen-closing) and proximal (lumen-opening) directions relative to amount block 58 with a pincher 60 coupled to a distal end of the rack 56.As the rack 56 is driven distally by the rotation of the pinion 54, thepincher 60 compresses a respective lumen in the cassette 28 against awall of the cassette 28. A position sensor 62 (e.g., an optical sensor,Hall effect sensor, etc.) may be included in the valve assembly 50 todetermine a position of the pincher 60 relative to the respective lumen.In this manner, an amount of closure of the respective lumen and/or anamount of fluid flow permitted through the respective lumen at theamount of closure may be determined. As will be described further below,the system 2 may utilize the closure information to adjust a volumeand/or pressure of fluid circulated through the uterus.

Referring back to FIG. 4, the valves 46 may include a number of valveassemblies 50 including similar rack and pinion assemblies and pincercombinations or other mechanisms corresponding to a number of lumens inthe cassette 28 to be selectively opened and closed. The valvearrangement 40 may further include a safety valve 64 which openswhenever a pressure within the lumen exceeds a predetermined maximumpressure or whenever an unsafe condition is detected.

The motor arrangement 42 includes a motor 66 (e.g., a DC brushlessmotor), a speed sensor 68 and an impeller coupling 70. Current suppliedto the motor 66 rotates an armature thereof which, in turn, rotates theimpeller coupling 70. In one exemplary embodiment, the impeller coupling70 includes one or more magnets which, when the cassette 28 is insertedinto the console 4, are magnetically coupled to one or more magnets onan impeller in the cassette 28 so that rotation of the impeller coupling70 rotates the impeller to drive fluid through the cassette 28 and intothe patient with no contact between fluid in the cassette 28 andcomponents of the console 4 outside the cassette 28. Those of skill inthe art will understand that the impeller coupling 70 and the impellerare an exemplary embodiment of any pump arrangement which may be used tooutput fluid from the cassette 28. The speed sensor 68 may be coupled tothe motor 66 to detect a rotational speed of the armature thereof todetermine, for example, a speed (and/or pressure) at which fluid isbeing circulated through the cassette 28 and/or the uterus.

As shown in FIG. 6, an exemplary embodiment of the front side 30 of theconsole 4 includes the user interface 12, the display screen 14 and thekeypad 16 which may be controlled by a user interface printed circuitboard (PCB) 70 which interprets user input entered via the keypad 16 anddisplays the content on the display screen 14. A screen cover 72 may beoverlaid on the display screen 14 to protect and allow cleansingthereof. The disposable overlay described above is preferably overlaidon the screen cover 72. A speaker 74 disposed within the console 4 maybe utilized to provide to the operator audible signals such as, forexample, voice instructions, warning signals, etc. which, when used inconjunction with the visual content presented on the display screen 14facilitate operation of the system 2. Additionally, the audible outputmay be useful when, for example, two persons are working in conjunctionto perform the ablation procedure. That is, the operator may bemonitoring operation of the system 2, while a physician and/or nurse maybe monitoring the fluid circulation through the uterus. The audibleoutput makes both persons aware of the progress of the ablationprocedure regardless their fields of view.

As shown in FIG. 7, the chassis 38 in the console 4 according to theexemplary embodiment is encased by the right, left, front and rear sides30, 32, 34, 36 of the housing 10. A power arrangement 76 mounted on thechassis 38 includes a power PCB 78, a toroid 80, a line filter 82 and apower supply 84 coupled to, for example, a port for receiving a linevoltage. For example, the power supply 84 may have a power cordextending therefrom to be plugged into a wall outlet, or the port mayreceive a plug as part of an extension cord. The line filter 82 treatsthe power to, for example, eliminate surges, harmonic transientcurrents, spikes, etc. in the current being delivered to the console 4.The filtered current is then transmitted to the power PCB 78 whichdistributes power to operational components of the system 2. The toroid80 operates as a transformer, providing electrical isolation betweencircuits in the console 4.

Also mounted on the chassis 38 is a motor controller 86 which receivesinstructions from a controller 44 to control operation of the motor 66.The controller 44, which is shown in FIG. 4, may be a central processingunit which coordinates operation of the system 2 during the ablationprocedure. That is, the controller 44 may process an instruction setstored in a memory for controlling the user interface 12, the motor 66,the valves 46, the safety valve 64, etc. during the ablation procedure.An exemplary use of the system 2 for performing an ablation procedurewill be explained in more detail below.

FIGS. 8 and 9 show an exemplary embodiment of the cassette 28 accordingto the present invention. As noted above, the cassette 28 may beembodied in a housing 88 sized and shaped to fit within the slot 26 onthe console 4. For example, the housing 88 may include rails along itssidewalls which are received by guides on the sidewalls of the slot 26,allowing the cassette 28 to slide thereinto. Once in the slot 26, thecassette 28 may be mechanically locked in place (e.g., latches, hooks,etc.), gravitationally held in the slot 26, magnetically coupled to theconsole 4, etc. In one exemplary embodiment, the instructions providedon the user interface 12 may instruct the operator on how and when toinsert and remove the cassette 28. The console 4 may lock the cassette28 in the slot 26 to prevent removal during an ablation procedure.

The fluid from the IV bag enters the cassette 28 via a fluid supplylumen 90 which terminates in a reservoir 92. In this embodiment, a levelsensing board 94 is disposed within the reservoir 92 for monitoring avolume of fluid therein. During the ablation procedure, the controller44 compares the volume to a predetermined volume (or range thereof) todetermine whether fluid has been lost/leaked. Based on the results ofthe comparison, the system 2 may shut down or execute a predeterminedsafety procedure. In the exemplary embodiment, the level sensing board94 comprises a plurality of level sensors (e.g., capacitors) arrangedalong a height of the board 94. By analyzing signals received from thelevel sensors, the controller 44 may determine the volume of the fluidwithin the reservoir 92.

The safety procedure may be a set of instructions stored in anon-volatile memory of a complex programmable logic device (CPLD) in theconsole 4. Based on the results of the comparison, the controller 44 maytransmit a safety procedure initiation signal to the CPLD which thenexecutes the safety procedure. The safety procedure may also be executedif, for example, the controller 44 indicates that a component of thesystem 2 is non-responsive or otherwise malfunctioning. The CPLD mayalso execute the safety procedure if the controller 44 malfunctions.

The fluid in the reservoir 92 is directed into a heating chamber 96 byan impeller 98 which, as described above, is rotated by the impellercoupling 70 in the console 4. As shown in FIGS. 14 and 15, an exemplaryembodiment of the impeller 98 includes a plurality of veins 160 disposedon a first surface and a plurality of magnets 162 disposed on a secondsurface. Each of the veins 160 may be formed, for example, as a concaveprojection on the first surface and have a predefined spacing and anglerelative to adjacent veins. In this configuration, the fluid interfacingwith the impeller 98 is forced from a center of rotation thereof andinto the heating chamber 96. The magnets 162 may be embedded in theimpeller 98 having exposed surfaces flush with the second surface whichmagnetically couple to the magnets on the impeller coupling 70. Aninterface between the impeller 98 and the impeller coupling 70 may beconfigured so that only the first surface of the impeller 98 comes intocontact with the fluid, while the second surface is exposed on (and/orforms a part of) an external surface of the cassette 28. Alternatively,the impeller 98 may be fully enclosed within the cassette 28.

The heating chamber 96 includes a heating element 100 which heats thefluid therein. Operation of the heating element 100 may be based on atemperature measurement of the fluid obtained by a temperature sensor(e.g., thermistor) in the heating chamber 96. By monitoring thetemperature measurement, the controller 44 ensures that the fluidtemperature is within a predetermined range (e.g., a temperature hotenough to ablate tissue). Those of skill in the art will understand thatthe heating element 100 may further include a cooling element or bedeactivated when, for example, the ablation procedure has been completedand the remaining surface tissue in the uterus is to be allowed to coolor when a safety procedure is executed.

As shown in FIG. 13, the heating chamber 96, in this embodiment, issubstantially cylindrical with a fluid inlet 150 at a lower end thereof.The inlet 150, which receives fluid pumped from the impeller 98, isdirected substantially tangential to the cylinder so that the fluidswirls around the heating chamber 96 and is heated by the heatingelement 100 as it rises to an outlet at the top of the cylinder. Theheating element 100 extends substantially along a longitudinal axis ofthe cylinder so that the fluid travels around the heating element 100 ina substantially helical path as it rises in the heating chamber 96,maximizing energy transfer to the fluid.

When the fluid exits the heating chamber 96 after having reached thedesired temperature, it leaves the cassette 28 via a delivery lumen 102and passes into an introducer which is inserted into the uterus via thecervix. The fluid is circulated through the uterus and returned to thecassette 28 via a return lumen 104. The returned fluid is then passedthrough a filter 106 to remove any tissue remnants, coagulated plasma,etc. and fed back through the impeller 98 into the heating chamber 96.By continuously circulating the returned fluid while monitoring anyvolumes of fluid added/removed from the system 2, the controller 44detects any change from the initial fluid volume as described above todetermine a volume of fluid absorbed into the body. When the ablationprocedure has been completed, the fluid is drained into the drainage bagvia a drainage lumen 110.

Electrical signals generated by the temperature sensors in the heatingchamber 96 and the level sensors in the reservoir 12 are transferred tothe controller 44 via a communications circuit board 108 and digitized.The digitized signals are then converted into procedural data (e.g.,temperature data and volume data) which is analyzed by the controller 44to monitor the progress of the ablation procedure.

During progression of the ablation procedure, the controller 44configures alternative fluid flow paths through the cassette 28 byselectively controlling operation of the valves 46 to open and close thefluid flow lumens therein. FIG. 11 shows an open loop flow path usedduring priming and/or cooling stages of the ablation procedure. Forexample, the system primes by opening the supply valve 140 to permitfluid from the IV bag through the cassette 28 to the reservoir 92 andthrough the impeller 98 to the heating chamber 96 which is inactive atthis point through the safety valve 64 into a delivery (not shown) of anintroducer 112. The fluid exits the delivery lumen into the uterus andis drawn back from the uterus into a return lumen (not shown) of theintroducer 112 which passes the fluid back through the safety valve 64and out to a drainage bag via a drainage valve 142. When the system hasbeen primed, the valves of the cassette 28 are reconfigured to theclosed loop configuration of FIG. 12 for heating of the fluid andablation. Specifically, the drainage valve 142 is closed so that fluidcirculates from the reservoir 92, through the impeller 98 and theheating chamber 96 and into the uterus via the safety valve 64 and theintroducer 112. The fluid returning from the uterus via the return lumen104 of the introducer 112 passes through the safety valve 64 and thefilter 106 to return to the reservoir 92 via the middle valve 144 andcontinues to circulate through this path during the ablation procedure.In this configuration, the heating chamber 96 is active to raise thetemperature of the fluid to a desired level for ablation. In addition,in this configuration, the bypass valve 146 is opened when necessary tobleed off excess flow from the output from the heating chamber 96returning this bled-off fluid to the reservoir 92 without passingthrough the uterus. When the procedure has been completed, the drainagevalve 142 is opened and the bypass valve 146 and the middle valve 144are closed to return the system 100 to the open-loop configuration ofFIG. 11. The heating chamber 96 is deactivated at this point so thatfluid currently circulating in the cassette 28 flows through the uterusand passes through the drainage valve 142 to the drainage bag withoutfurther heating. After this fluid has been drained, fresh fluid from theIV bag is passed through the cassette 28 into the uterus atsubstantially room temperature to flow out into the drainage bag until adesired amount of cooling has been achieved. As would be understood bythose skilled in the art, cooling may also performed by continuing tocirculate the fluid through the closed loop while the heating element ispowered off.

Referring back to the exemplary embodiment of the cassette 28 shown inFIG. 8, a therapeutic agent chamber 101 may be formed in the cassette 28for storing a predetermined volume of a therapeutic agent. For example,up to 30 cc's of diluted or concentrated fluid may be stored in thetherapeutic agent chamber. The therapeutic agent is retained in thechamber 101 by a chamber valve 107 which is selectively opened andclosed by the controller 44 to open and close an output lumen of thechamber 101 in coordination with the ablation procedure. When thechamber valve 107 is open, the therapeutic agent is permitted to flow tothe impeller 98 (e.g., by gravity, suction created by rotation of theimpeller 98, etc.) via the output lumen and be pumped out of thecassette 28 into the uterus, as will be explained further below. In theexemplary embodiment, the therapeutic agent stored in the chamber 101may be a non-steroidal anti-inflammatory agent, a steroid, an analgesic(e.g., Ketorolac Tromethamine), an antimicrobial agent, an anesthetic orany combination thereof which may be used to reduce inflammation,discomfort, possibility of infection or any other deleterious effectassociated with ablating tissue or any other therapeutic agent.Preferably, the chamber 101 is thermally isolated within the cassette28, preventing adverse thermal effects to the therapeutic agent duringoperation of the heating element 100. In another exemplary embodiment,an external therapeutic agent source is coupled to the cassette 28 viathe fluid supply line 90 instead of or in addition to using the chamber101.

After being circulated through the uterus and ablating the endometriallining, the heated fluid is cooled and recirculated through the uterusto cool the uterine tissue. The controller 44 may then configure thevalves 46 to the open loop configuration to purge the cassette 28 of thefluid and subsequently reconfigure the valves 46 for the closed loopconfiguration to circulate the therapeutic agent through the uterus. Torelease the therapeutic agent into the fluid flow path in the cassette28, the controller 44 closes the supply, drainage and bypass valves 140,142, 146 and opens the chamber and middle valves 107, 144. Thetherapeutic agent is released from the chamber 101 into the impeller 98and is pumped through the heating chamber 96 (with the heating element100 deactivated), out of the cassette 28 and into the uterus. Uponreturn from the uterus, the therapeutic agent is passed through thefilter 106, into the reservoir 92 and back into the impeller 98 forrecirculation out of the cassette 28 and into the uterus. Circulation ofthe therapeutic agent may occur for a predetermined time selected sothat the therapeutic agent has the intended therapeutic effect (e.g., isabsorbed by and/or coats the uterine tissue).

Those of skill in the art will understand that the cassette 28 mayinclude any number of therapeutic agent chambers with each holding anytype of therapeutic agent. In an exemplary embodiment with multipletherapeutic agent chambers, the controller 44 may manipulate chambervalves corresponding to each of the chambers in conjunction with theablation procedure. For example, a first chamber may include a steroid,while a second chamber may include an antimicrobial agent. Thecontroller 44 may selectively open and close the corresponding chambervalves to circulate the steroid and the antimicrobial agent through theuterus successively or concurrently at desired times before, duringand/or after the procedure.

In one exemplary embodiment, a resealable port (not shown) may bedisposed on the cassette 28 allowing a therapeutic agent to be injectedto and/or removed from the chamber 101. In this embodiment, the cassette28 may be reusable between patients or for a single patient. Forexample, if additional volume of the therapeutic agent is required(e.g., based on the surgical procedure), the physician may re-fill thechamber 101 with the therapeutic agent via the resealable port.

As shown in FIG. 10, an introducer 112 according to an exemplaryembodiment of the present invention is coupled to the cassette 28 viatubes 103 and 105 to deliver fluid to the uterus and to return the fluidfrom the uterus to the cassette 28. The tubes 103, 105 are coupled tothe delivery and return lumens 102, 104, respectively, of the cassette28 and to fluid delivery and return lumens (not shown) within a sheath113 of the introducer 112. The fluid delivery and return lumensterminate at respective openings at a distal end 118 of the sheath 113which, when the introducer 112 is in an operative positions, is locatedwithin the uterus. The introducer 112 may optionally include a visionsystem to allow visualization of the operative area. Those of skill inthe art will understand that the vision system may be substantiallysimilar to the systems in conventional endoscopes (e.g., fiber optic orCCD-based systems). Alternatively, users may rely on the vision systemof an endoscope or other instrument inserted through the introducer 112,as described below.

The introducer 112 includes a grip 114 (e.g., an ergonomic handle)coupled to the sheath 113 and a scope connector 116 for receiving avisualization device, such as an endoscope. The grip 114 facilitatesholding and manipulation of the introducer 112 with a single hand whilethe operator uses his free hand to interface with the console 4, adjustthe visualization device, manipulate the patient's anatomy, etc. Thescope connector 116 according to this embodiment is disposed on aproximal end of the introducer 112 and provides an attachment point forthe visualization device (e.g., a hysteroscope, an endoscope) so thatthe visualization device may be passed distally through a visualizationlumen in the introducer 112 and extended out of the distal end 118.Thus, the operator may visually monitor insertion of the introducer 112into the uterus.

The scope connector 116 may comprise an optional locking ring 117 and ascope adapter 120 which allow the introducer 112 to be adjusted toaccommodate visualization devices of varying lengths. The visualizationdevice is inserted into the proximal end of the introducer 112 throughthe scope connector 116 and locked thereto using the locking ring 117.The user then depresses the scope adapter 120 releasing the scopeadapter 120 from a current locking aperture 121. This allows the scopeconnector 116 to slide proximally out of or distally into the introducer112 so that, when the visualization device has been inserted through thesheath 113 to a desired position in the uterus, the scope connector 116supports the portion of the visualization device extending out of theintroducer (e.g., a proximal end of an endoscope immediately distal ofthe control handle). Those of skill in the art will understand that thescope connector 116 may be implemented as any mechanism which allows thelength of the introducer 112 to be adjusted to and maintained at a newlength. For example, as shown in FIG. 10, the scope adapter 120 isformed as a projection on an outer surface of a distal portion of thescope connector 116 received in and movable between one of a number oflocking apertures 121 formed on the grip 114. Partial barriers may beformed between each of the locking apertures 121 to retain the scopeadapter 120 in a selected one of the locking apertures 121 maintaining aselected length of a portion of the scope connector 116 projecting fromthe proximal end of the introducer 112. In another embodiment, a rackmay be formed on the distal portion of the scope connector 116 matingwith a gear in the grip 114 so that rotation of the gear extends andwithdraws the scope connector 116 relative to the grip 114. A ratchetmay be provided to maintain the gear in a fixed position relative to therack, thereby maintaining the desired position of the scope connector116 relative to the grip 114.

The grip 114 may further include an optional tenaculum stabilizer 122.For example, during the ablation procedure, a tenaculum may be employedaround the cervix to enhance the seal of the cervix around the sheath113 of the introducer 112. A tenaculum that has been clamped around thecervix may then be coupled to the introducer 112 to ensure that theintroducer 112 remains at a desired position within the uterus and isnot inadvertently withdrawn therefrom. That is, it is important to makesure that the distal end of the sheath 113 is not withdrawn proximallyfrom the uterus during the procedure or non-targeted tissue will beexposed to the ablation fluid. Thus, a portion of the tenaculum ispassed over the tenaculum stabilizer 122 preventing movement of thesheath 113 proximally relative to the tenaculum. That is, once atenaculum has been locked in position on tissue, the tenaculum can beslipped over the tenaculum stabilizer 122. The tenaculum stabilizer 122is moved to a proximal-most position permitted by the tenaculum.Specifically, in the exemplary embodiment, the tenaculum stabilizer 122includes a fin slidably mounted on a rail 124 formed on the grip 114.The fin includes a hook which may receive finger grips or a crossbar ofa tenaculum as would be understood by those skilled in the art. When thetenaculum is coupled to the tenaculum stabilizer 122, the operatorselects a tension to be applied between the tenaculum and the introducer112 by moving the fin along the rail 124. A positioning mechanism (e.g.,ratchet, latch, clip, etc.) may be used to maintain a position of thefin relative to the rail 124, as would be understood by those skilled inthe art. Such a tenaculum stabilizer device is described in a U.S.Provisional Patent Application Ser. No. 60/971,409 filed on Sep. 11,2007 and entitled “TENACULUM STABILIZER DEVICE,” naming as inventorsChristopher Oskin, Brian MacLean, Stephen Keaney, Jozef Slanda andJeffrey Zerfas. The entire disclosure of this application is herebyincorporated by reference herein.

The introducer 112 may further include an optional cervical seal 126separated from a distal end of the sheath 113 by a distance selected toensure that, when the distal end of the sheath 113 is in a desiredposition within the uterus, the seal 126 is located within the cervixproximal to the cervical os C. When the distal end 118 of the introducer112 is introduced into the uterus, the elasticity of the cervix providesa substantially fluid-tight seal around the sheath 113. However, tominimize the risk of ablation fluid escaping through the cervix todamage non-targeted tissue, the fluid-tight seal may beenhanced/maintained using the cervical seal 126. In the exemplaryembodiment, the cervical seal 126 is formed as a flexible membrane 127which overlies a wire mesh 129, a proximal end of which abuts a distalend of an expander member 130. The wire mesh 129 may, for example, beformed as a PEEK braid or an SS braid while the membrane 127 may, forexample, be formed of silicone, a rubber material, or C-Flex. A distalend of the cervical seal 126 is fixed to the sheath 113 while a proximalend is slidable along the sheath 113.

A seal actuator 128 comprises a ring rotatably mounted on the sheath 113and coupled to the expander member 130 which, in this embodiment, isformed as an oversheath telescopically mounted over the sheath 113. Thering may be coupled to the oversheath in such a manner that rotation ofthe ring moves the oversheath proximally and distally over the sheath113. For example, an outer portion of the proximal end of the oversheathmay be threaded to mate with threads on an inner portion of the ring ofthe seal actuator 128 so that, when the ring is rotated in a firstdirection, the expander member 130 slides distally along the sheath 113pushing the proximal end of the mesh 129 distally causing the cervicalseal 126 to expand radially away from the sheath 113.

As shown in FIG. 16, it is preferable that expansion of the cervicalseal 126 is executed when it is within the cervix proximal of thecervical os C so that none of the targeted tissue is covered by the seal126. In the exemplary embodiment, the sheath 113 is moved distally untilthe distal end 118 thereof is within the uterus. The sheath 113 is thenwithdrawn proximally to minimize a projection of the sheath 113 into theuterus maximizing a field of view of the vision system. While in thisposition, the cervical seal 126 is positioned entirely within the cervixwith a distal end of the seal 126 proximal of the cervical os C. Theexpander member 130 engages the proximal end of the cervical seal 126and pushes the proximal end distally along the sheath 113 into theexpanded position shown in FIG. 16. In the expanded position, themembrane 127 substantially engages an inner wall of the cervix enhancingthe seal provided by the natural resilience of the wall of the cervix.The distal end of the seal 126 is preferably located approximatelybetween 1 and 4 mm proximal of the distal end 118 of the sheath 113 andis more preferably approximately 2 mm proximal of the distal end 118. Inaddition, the seal 126 preferably expands to an OD of between 8 and 14mm and more preferably expands to an OD of approximately 11 mm.

Rotation of the ring in a second direction withdraws the expander member130, allowing the cervical seal 126 to return to its unexpanded statethrough the bias of the mesh 128 which tends toward the unexpandedstate. Alternatively, the proximal end of the mesh 129 may be coupled tothe distal end of the expander member 130 so that, as the expandermember 130 is moved proximally, the mesh 129 is drawn back into theunexpanded state against a bias of the mesh 128 which tends to expandthe seal 126.

In an exemplary use, the system 2 according to the present invention maybe used to ablate the endometrial lining of the uterus. When the console4 is activated, the display screen 14 may show (and the speaker 74 mayprovide) a pre-operative instruction set. For example, the instructionset may prompt the operator to hang the IV bag and the drainage bag. Thecontroller 44 may then detect whether the cassette 28 has been insertedinto the slot 26 and provide instructions regarding a procedure forconnecting the cassette 28 to the IV bag, the drainage bag and theintroducer 112. In addition, the controller 44 may determine, upondetecting the presence of the cassette 28, whether the cassette 28 hasbeen previously used and prevent operation or take other pre-ordainedsteps if prior use is detected.

The pre-operative instruction set may also instruct the operator toadjust a height of the console 4 to be substantially equal with a heightof the uterus or to achieve some other desired relationship between theheight of the console 4 and that of the uterus. In the exemplaryembodiment, the height of the console 4 is varied by adjusting the stand8 using a light beam (e.g., laser) emitted from the beam exit port 24 toensure that the console 4 is level with the uterus. When the console 4is level with the uterus, the operator may initiate the ablationprocedure by inserting the introducer 112 into the uterus via the cervixand expanding the cervical seal 126 within the cervix. The controller 44may then configure the cassette 28 for the open loop flow path byopening the fluid supply and drainage valves 140, 142 and circulate apre-operative fluid through the uterus, priming the endometrial liningfor ablation.

During a heating stage of the ablation procedure, the fluid from the IVbag enters the cassette 28 and is heated to a predetermined temperature(e.g., approximately 85-90° C.) as indicated by signals generated by thetemperature sensors in the heating chamber 96 and transferred to thecontroller 44 in the console 4 via the communications board 108. Thesignals may be digitized and analyzed to determine when the fluid hasreached the predetermined temperature. Prior to the fluid being heated,the controller 44 configures the cassette 28 for the closed loop flowpath by closing the fluid supply and drainage valves 140, 142 andopening the middle valve 144 so that fluid returning from the uterus isfed back into the reservoir 92, as described above.

When the fluid has reached the predetermined temperature, the console 4initiates a treatment stage circulating the heated fluid through theintroducer 112 into the uterus to ablate the endometrial lining asdescribed above in regard to FIG. 12. The heated fluid is delivered tothe uterus via the delivery lumen in the sheath 113, removed from theuterus via the removal lumen in the sheath 113 and returned to theconsole 4 where it is filtered by the filter 106 and returned to becirculated through the uterus for a predetermined duration (e.g.,approximately 10 minutes) to ablate the endometrial lining. Thetreatment stage may further include a cooling cycle in which the heatedfluid is allowed to cool and then circulated through the uterus toabsorb heat from the exposed tissue aiding in the healing process. Whenthe treatment stage has been completed, the console 4 employs a draincycle, emptying the fluid in the system into the drainage bag.

In a post-treatment cycle, the controller 44 may configure the cassette28 in the closed loop configuration and open the chamber valve 107,allowing the therapeutic agent in the chamber 101 to flow into theimpeller 98. The therapeutic agent is then pumped out of the cassette 28and into the uterus for circulation therethrough. When the therapeuticagent is removed from the uterus, it is passed through the filter 106and into the reservoir 92. The level sensing board 94 may monitor alevel of the therapeutic agent to ensure that a volume of thetherapeutic agent being circulated through the uterus is substantiallyconstant. However, those of skill in the art will understand that thevolume may change, because a portion of the therapeutic agent may beabsorbed by the uterine tissue, as medically intended.

Those of skill in the art will understand that various hardware andsoftware-based variations may be implemented in the system 5 accordingto the present invention. For example, the height-adjusting mechanism onthe stand 8 may be controlled by position data generated by a positionsensor on the introducer 112. After the introducer 112 has been insertedinto the uterus, the position data may be analyzed to determined aheight of the introducer above the floor. If the height of the console 4is not properly aligned with the height of the introducer 112, an alarmmay be activated or an automatic height adjusting mechanism may adjustthe height of the console 4 to the desired level. In addition, apressure transducer may be coupled to the distal end 118 of theintroducer 112 to sense the fluid pressure within the uterus. Thepressure transducer may provide pressure data to the controller 44 whichdetermines whether the pressure is within a predefined operable range,and if the pressure is outside of the range, the controller 44 mayexecute a safety procedure.

The present invention was described with reference to specific exemplaryembodiments. Those skilled in the art will understand that changes maybe made in details, particularly in matters of shape, size, material andarrangement of parts. For example, the invention is not limited tomethods and devices for the thermal ablation of the uterine lining.Accordingly, various modifications and changes may be made to theembodiments. The specifications and drawings are, therefore, to beregarded in an illustrative rather than a restrictive sense.

What is claimed is:
 1. A method for ablating target tissue within ahollow organ, comprising: heating an ablation fluid ex-vivo to apredetermined temperature; pumping the heated ablation fluid from acassette via a fluid delivery lumen into an introducer inserted into ahollow organ containing the target tissue to thermally ablate the targettissue with the heated ablation fluid; after the ablation fluid has beencirculated through the hollow organ, withdrawing the ablation fluid fromthe hollow organ via a fluid return lumen in the introducer, the fluidreturn lumen coupled to the cassette; and pumping a therapeutic agentfrom the cassette via the fluid delivery lumen into the introducerinserted into the hollow organ.
 2. The method according to claim 1,further comprising the step of, prior to pumping the therapeutic agent,draining the ablation fluid from the cassette.
 3. The method accordingto claim 1, further comprising, after the therapeutic agent has beencirculated through the hollow organ, withdrawing the therapeutic agentfrom the hollow organ via the fluid return lumen in the introducer. 4.The method according to claim 1, wherein the ablation fluid is saline.5. The method according to claim 1, wherein the therapeutic agent is oneof a non-steroidal anti-inflammatory agent, a steroid, an analgesic andan antimicrobial agent.
 6. The method according to claim 1, furthercomprising filtering the withdrawn ablation fluid.
 7. The methodaccording to claim 6, further comprising reheating the filtered ablationfluid and recirculating the reheated ablation fluid through the holloworgan.
 8. The method according to claim 6, further comprising coolingthe filtered ablation fluid and recirculating the cooled ablation fluidthrough the hollow organ to cool the hollow organ prior to pumping thetherapeutic agent therein.
 9. An ablation system, comprising: a consoleincluding a pump motor; a cassette releasably coupleable to the consoleand including a reservoir configured to receive a fluid from an externalsource via a fluid supply lumen, a therapeutic agent chamber containinga therapeutic agent, and an impeller interfacing with the pump motor ofthe console to deliver one of the fluid and the therapeutic agent to ahollow organ via a delivery lumen; a heating element heating the fluidreceived within the reservoir such that the fluid is at a desiredtemperature for thermal ablation of a target tissue within the holloworgan when the fluid is delivered to the hollow organ; and a returnlumen withdrawing one of the heated fluid and the therapeutic agent fromthe hollow organ to the cassette.
 10. The system according to claim 9,wherein the fluid is saline.
 11. The system according to claim 9,wherein the therapeutic agent is one of a non-steroidalanti-inflammatory agent, a steroid, an analgesic and an antimicrobialagent.
 12. The system according to claim 9, wherein the impeller ismagnetically coupled to the pump motor.
 13. The system according toclaim 9, further comprising a valve arrangement altering a supply offluid to the impeller so that, when the valve arrangement is in a firstconfiguration, a first fluid flow path of the cassette in communicationwith the fluid supply lumen is open and a second fluid flow path of thecassette in communication with the fluid chamber is closed, and when thevalve arrangement is in the second configuration, the first fluid flowpath is closed and the second fluid flow path is open.
 14. The systemaccording to claim 13, wherein, when the valve arrangement is in thesecond configuration, the valve arrangement opens a fluid outlet lumenof the fluid chamber so that the therapeutic agent flows to theimpeller.
 15. The system according to claim 13, wherein, when the valvearrangement is in the second configuration, the valve arrangement closesa fluid supply lumen connecting the cassette to the external fluidsource.
 16. The system according to claim 13, wherein the valvearrangement includes at least one pincher valve.
 17. The systemaccording to claim 9, wherein the cassette includes a fluid storingreservoir and a level sensor outputting a signal corresponding to alevel of fluid in the reservoir.
 18. The system according to claim 17,wherein the console includes a controller determining a volume of fluidcirculating through the cassette as a function of the signal.
 19. Thesystem according to claim 9, further comprising a filter filtering thefluid and the therapeutic fluid when returned to the cassette via afluid return lumen coupled thereto.
 20. The method according to claim 1,wherein the therapeutic agent is selected from a group consisting ofblood products, nutritive solutions, drugs and combinations thereof. 21.The system according to claim 9, wherein the therapeutic agent isselected from a group consisting of blood products, nutritive solutions,drugs and combinations thereof.